As is generally known to those familiar with debarking machines of the ring rotor type, several debarking tools are circularly arranged around the central opening of the rotor and extend generally radially inwardly with their cutting edges positioned adjacent the axis of the rotor. When the rotor is rotated and a log is being fed into the rotor inlet, the leading butt end of the log engages the debarking tools and causes them to rotate outwardly in opposition to conventional resilient means so that the cutting edges of the tools climb upwardly onto the peripheral surfaces of the log for debarking same.
In recent years it has become an increasingly prevalent practice to use powered cutting jaws instead of powered cutting saws in the harvesting of trees. While this technique has facilitated the felling and harvesting of trees, the trees no longer have relatively square cut butt ends but instead have irregular somewhat conically shaped pinched ends. This has resulted in new problems attendant to the debarking of trees. As is well known, conventional debarking machines have their circularly arranged debarking tools each provided with a climbing edge for the purpose of engaging the leading butt end of the log and for quickly moving the debarking tool outwardly to the periphery of the log for performing debarking thereof. Debarking tools with climbing edges thereon are disclosed in U.S. Pat. Nos. 2,880,771 (Annis, Jr.); 3,709,272 (Bowers); and 3,973,607 (Jonsson), for example.
With this new technique of harvesting trees with powered cutting jaws, no longer are the logs provided with a relatively square butt end for ready engagement of the climbing edge of the debarking tool therewith. This has resulted in the relatively short rearwardly projecting climbing edge of the prior art debarking tools not always being engaged by the logs. Thus the debarking tools were not always moved sufficiently out of the longitudinal path of travel of the log through the debarking machine, with the result that breakage of the tools has occurred due to the impact of the logs with the debarking tools.
Further, prior art debarking tools typically have cutter members on the free ends thereof that are likely to be engaged by the leading end of each successive log being fed and since such cutter members or portions thereof are preferably made from a hard metal, such as sintered carbide, and which is therefore quite brittle, such cutter members may be fractured upon impact thereof by the leading butt end of a log, thus requiring replacement of the cutter members.